"The lineage resulted in Homo floresiensis, found at Liang Bua."
Brumm, Australian colleagues, and collaborators from the Geological Research and Development Center in Bandung, Indonesia, will report their analysis in tomorrow's issue of the journal Nature.
The older Flores tools were found among remains of dwarf elephants, komodo dragons, rats, and other animals, according to the paper.
Richard Potts is the director of the Human Origins Program at the Smithsonian Institution in Washington, D.C. He said the concept of a continuous toolmaking tradition on Floresa remote and isolated islandmakes sense.
However, the new study fails to prove continuity of a stone-toolmaking tradition passed down an ancestral line.
The study authors "have only two data points, and they are just connecting the two points," Potts said.
To prove continuity, the team needs tools from a few other Flores sites dated between the 800,000-year and 12,000-year marks, he added.
And regardless of continuity, Potts says, the new study fails to resolve the debate over who the hobbit-like people are descended from.
According to one theory, they resulted from island dwarfinga process by which species tend to shrink over generations on small islands where food is scarceof the large-bodied early human Homo erectus.
But recent studies have suggested that the bone structure of the hobbit-like people is more like smaller-bodied australopithecinesa group of human ancestors that are not considered human.
"That part remains a mystery. I don't think the stone tools will tell us [the answer]," Potts said.
The relative simplicity of the Flores tools implies that a sophisticated modern-human brain was not necessary to make the tools, according to study author Brumm. Even so, the toolmakers were capable craftspeople, he adds.
"There is a lot of precision in the manufacture of these tools, which is striking because traditional interpretations of early hominin tool technology in Southeast Asia imply that it is crude and rough flaking," he said.
Potts said the simple yet elegant Flores tools force scientists to rethink the factors that drove the evolution of the big brains humans benefit from today.
"There's a long tradition in [the study of fossil hominids] that somehow brain size and complexity of technology are tied up with one another," he said.
According to Potts, perhaps the need to process larger geographical and social landscapes drove evolution towards bigger brainsa need not found on tiny Flores.
For example, in Africa around the time modern humans originated, stone toolmakers were using resources from more than 62 miles (100 kilometers) away, Potts says.
The tools "were exchanged between groups. And so you have this spatial manipulation of the landscape, including the social landscape, associated with all that brainpower," he said.
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